GB204299A - Improvements in key clutches - Google Patents

Abstract

204,299. Bliss Co., E. W., (Assignees of Strout, R. W.). Sept. 22, 1922, [Convention date]. Clutches, claw; operating clutches.-In segmental-key clutches for presses, comprising a locking-key to prevent over-running and an operative connection between the driving-key and the locking-key for disengaging the locking-key when the driving-key is disengaged, this connection is such as to permit the locking-key to be held out of operation without affecting the actuation of the driving-key. A heavy driving-pulley 10 has notches 12 formed in its hub portion 99 and bears by extensions 104, 105 on collars 100, 101 keyed to the crank-shaft 15, there being some clearance between the parts 15, 99. A driving- key 18, bearing in recesses 23 in the shaft 15 and collars 100, 101, has a central segmental portion 20 adapted to engage a notch 12 under the action of a coil spring 30. The key 18 is rocked to the disengaged position by a catch 37, adapted by its connections 39, 42, 45 to a spring-pulled treadle rod 38 to be turned into the path of an arm 3 on the key, as described in Specification 211,280. A locking-key 60, similar to the key 18 but adapted to turn oppositely, is arranged under spring action to engage a second notch 12 to prevent over-running as soon as there is driving- contact between the key 18 and the rear face of the first notch. As shown in Fig. 5, the engagement of teeth 68, 69 on the keys 18, 60 positively causes disengagement of the locking-key with the driving-key but does not constrain the engaging movement of either. The tooth 68 may be formed on a separate collar 71, Figs 1 and 7, secured on a squared part 72 of the key 18. The coil springs 30 are housed in a cap 110 and secured at their outer ends to rotatable discs 80, whereby the spring tension may be relieved to throw the key 60 out of action, in order to allow the operator to " bump " the press, or to throw both keys out of action to protect him when setting dies &c. Pins 90 work in grooves 93 to limit the motion of the discs 80, and set-screws 87 are provided to lock them.